Mechanical pencil



FIG. 1 is a perspective view of the front, bottom and left side of a mechanical pencil showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is an enlarged left side view thereof; and,

FIG. 6 is an enlarged right side view thereof. 

The ornamental design for a mechanical pencil, as shown and described. 